Compilare: main.cpp: In function 'int main()': main.cpp:13:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<=strlen(s)-1;++i) ~^~~~~~~~~~~~~ main.cpp:14:7: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] if(s[i]>='a'&&s[i]<='z') ^ main.cpp:20:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<=strlen(s)-1){ ~^~~~~~~~~~~~~